Sift-proof patch valve for plastic shipping bags



y 1967 J. J. QUACKENBUSH 3,322,326

SIFT-PROOF PATCH VALVE FOR PLASTIC SHIPPING BAGS Filed Feb. 21. 1966firs-.5. 11:5 4..

JOHN J. QUACKEN B USH INVENTOR.

United States Patent 3,322,326 SIFT-PROOF PATCH VALVE FOR PLASTICSHIPPING BAGS John J. Quackenbush, Monroe, Conn., assignor to NationalDistillers and Chemical Corporation, New York,

N .Y., a corporation of Virginia Filed Feb. 21, 1966, Ser. No. 528,961Claims. (Cl. 229-625) This invention relates to filling valves forplastic bags,

and more specifically relates to a novel external patch valve having afolded central portion which defines a barrier between the patchentrance and the bag entrance. Many types of valve are well known forplastic bags which permit filling of the bag through anfilling spout,with the valve sealing the bag opening when the spout is removed. Acommon type valve for this purpose uses a single or multiple sleevearrangement which must be built into the interior of the bag. Suchvalves are expensive and difficult to produce. Moreover, the sleevetypevalve, as well as most of the other prior art valves, usually do notautomatically form a good seal when the filling tube is removed. Thosevalves which are arranged to be self-sealing are commonly found to beleaky, and are difiicult to open.

A primary object of the present invention is to provide a novel andinexpensive valve for plastic shipping bags which is connected to theexterior of the bag and which defines an effective self sealing channelinto the interior of the bag and which provides easy access to theinterior of the bag by a filling spout.

In accordance with the invention, one panel of the bag is provided witha conveniently located slit, and this slit is then covered by anexterior patch having a folded central section. The exterior patch isthen sealed on three sides to the bag exterior and around the slit withthe fourth side defining a spout opening leading to the slit opening inthe bag. However, the folded section is positioned in the spout channeland in front of the slit, thereby to define a resilient, self-sealingclosure in the spout channel to prevent sifting or leakage of the bagcontents through the spout channel and to prevent the passage ofmoisture through the spout channel. Moreover, the expansion of the bagby its contents will tend to further compress the folded section withinthe spout channel to increase the effectiveness of the seal.

Therefore, an important object of this invention is to form an effectiveself-sealing valve by the use of a single sheet of plastic connected tothe exterior of a bag.

Another object of this invention is to provide an inexpensive butextremely effective self-sealing valve for plastic bags.

These and other objects of this invention will become apparent from thefollowing description when taken in connection with the drawings, inwhich:

FIGURE 1 is an exploded perspective view of a plastic bag and the singleplastic sheet having a rolled section therein which is connected to theexterior of the bag to define a filling valve.

FIGURE 2 is a front view of the bag of FIGURE 1 with heat seal sectionsshown by double cross-hatching.

FIGURE 3 is a cross-section of FIGURE 2 taken across line 3-3 in FIGURE2.

FIGURE 4 is a view of the right-hand side of FIGURE 2 and illustratesthe spout channel opening.

FIGURE 5 is a cross-sectional view of FIGURE 2 taken across line 55 inFIGURE 2.

FIGURE 6 is similar to FIGURE 5 but shows the insertion of a fillingspout through the spout channel and into the bag interior.

FIGURE 7 is a cross-sectional view of FIGURE 2 taken across line 7-7 inFIGURE 2.

3,322,326 Patented May 30, 1967 Referring first to FIGURES 1, 2 and 3,there is illustrated a typical plastic bag having front and rear panels20 and 21, respectively, which are connected across their bottom by asuitable heat seal 22. Such bags are commonly formed of blown plastictubing which is cut to suitable length. However, the invention isapplicable to any type of plastic bag structure, including gusseted bagswhich are formed in any desired manner.

Any convenient part of the bag at which it is desired to receive afilling spout is then provided with a slit, shown as slit 23, extendingfrom the top of panel 20 and off-set from the side edge of the bag.

In accordance with the invention, a spout channel 24 (FIGURES 4, 5, 6and 7), which is self-sealing and which leads to slit '23, is formed bya single plastic sheet or patch 25 which is connected to the exterior ofpanel 20 in a simple and inexpensive manner. Patch 25 can be of the samematerial as the bag and is preferably heat sealable to the bag panelmaterial. Typically, the bag panels and patch 25 could be ofpolyethylene having a thickness of 10 mils. The sheet 25, in accordancewith the fold or rolled section 26, as shown in FIGURES 1, 2, 5 and 6,which defines a resilient, self-sealing body extending across the spoutchannel 24, as will be more fully described.

Patch 25 is securedto panel 20' by plastic heat seals 26 and 27 Whereseal 26 is behind slit 23, while seal 27 extends along the bottom ofpatch 25. Note that other means of securing patch 25 to the exterior ofpanel 20 could also be used such as cementing, or the like. Thereafter,an upper heat seal 28 completely seals through both panels 20 and 21 andthe top of patch 25 thereby to define channel 24 extending from slit 23,between the exterior surface of panel 20 and the interior surface ofpatch 25 to the open end of patch 25 at the right in FIGURE 2.

In accordance with the invention, the fold, or roll 26, which may be .apartial convolution or one or more convolutions in the patch 25transverse to the channel 24 is captured at its outer edges by heatseals 27 and 28 to prevent unrolling, whereby the rolled shape isretained and presses against the exterior surface of panel 20 withinchannel 24. This then defines a self-sealing closure for channel 24,which is further pressed closed when the bag is filled by the outwardbulging of the bag panels 20 and 21.

In addition to forming an effective sealing barrier in channel 25, thenovel patch valve also permits easy entrance to a filling spout, asshown in FIGURE 6, where the spout presses the roll section 26 outwardlyand passes through slit 23. Note that the roll section 26 normally willpress the end of channel 25 slightly open for such easy access. After.the bag is filled, and the filling spout is by the rolled or foldedsection 26, as shown in FIGURE 5.

has been described with re The embodiments of the invention in which anexclusive privilege or property is claimed are defined as follows:

said plastic bag having front and rear panels oined together; said frontsaid patch valve panel, the interior surface of said patch valve andsaid partially enclosed sealing line which extends from said opening tothe region of said patch valve which is unsecured to said exteriorsurface; said patch valve having a rolled section interposed betweensaid opening and unsecured region; said rolled section terminating ateither end on said partially enclosed sealing line.

2. The device as set forth in claim 1 wherein said patch valve is ofthermoplastic material; said partially enclosed line of securementcomprised of a heat seal.

3. The device as set forth in claim 2 wherein said opening comprises aslit in said front panel.

4. The device as set forth in claim 3 wherein said slit extends from thetop of said front panel parallel to the side edges of said bag.

5. The device as set forth in claim 4 wherein said line of securementcomprises first, second and third heat seals; said first heat sealextending across the top of said bag and sealing said front and rearpanels and the top of said patch valve together; said second heat sealextending parallel to said slit and spaced laterally to one side of saidslit and sealing one side of said patch valve to said front panel; saidthird heat seal extending perpendicular to said slit and crossing thebottom of said slit and sealing the bottom of said patch valve to saidfront panel; said rolled section extending parallel to said slit andspaced laterally to the opposite side of said slit; said first and thirdheat seals, respectively, extending across the opposite ends of saidrolled section and securing said ends to said front panel.

References Cited UNITED STATES PATENTS 3,209,804 10/19 65 Walker 229-625FOREIGN PATENTS 1,371,745 7/1964 France.

JOSEPH R. LECLAIR, Primary Examiner. D. M. BOCKENEK, Assistant Examiner.

1. A PATCH VALVE FOR A PLASTIC BAG; SAID PLASTIC BAG HAVING FRONT AND REAR PANELS JOINED TOGETHER; SAID FRONT PANEL HAVING AN OPENING THERETHROUGH; SAID PATCH VALVE COMPRISING A SINGLE ELONGATED SHEET DISPOSED ON THE EXTERIOR OF SAID FRONT PANEL AND OVERLYING SAID OPENING; SAID PATCH VALVE SECURED TO SAID FRONT PANEL ALONG A LINE ONLY PARTIALLY ENCLOSING SAID OPENING AND DEFINING A CLOSED CHANNEL BOUNDED BY THE EXTERIOR SURFACE OF SAID FRONT PANEL, THE INTERIOR SURFACE OF SAID PATCH VALVE AND SAID PARTIALLY ENCLOSED SEALING LINE WHICH EXTENDS FROM SAID OPENING TO THE REGION OF SAID PATCH VALVE WHICH IS UNSECURED TO SAID EXTERIOR SURFACE; SAID PATCH VALVE HAVING A ROLLED SECTION INTERPOSED BETWEEN SAID OPENING AND UNSECURED REGION; SAID ROLLED SECTION TERMINATING AT EITHER END ON SAID PARTIALLY ENCLOSED SEALING LINE. 